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Ohio Journal of Science (Ohio Academy of Science)
Ohio Journal of Science: Volume 38, Issue 5 (September, 1938)
1938-09
The Rate of Growth of Finger Nails in Relation
to the Cystine Content in Arthritics
Edwards, Linden F.
The Ohio Journal of Science. v38 n5 (September, 1938), 244-250
http://hdl.handle.net/1811/2963
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THE RATE OF GROWTH OF FINGER NAILS IN
RELATION TO THEIR CYSTINE CONTENT
IN ARTHRITICS
LINDEN F. EDWARDS
Department of Anatomy, The Ohio State University
INTRODUCTION
Several investigators, notably Berthold (1), Dufour (2),
Sharpey-Schafer (3), Heller (4) and Voit (5), employing different
methods of measurement, have reported that finger nails grow
on the average of 1 mm. in ten days, that is, one-tenth of a
millimeter (0.100 mm.) per diem. Results obtained by the
writer on the growth of finger nails of a large number of apparently normal, healthy individuals agree in general with this rate.
As to the factors upon which nail growth depends numerous
ones have been suggested. Thus Berthold found that nails
grow more rapidly in summer than in winter, in children than
in adults, on the right than on the left hand and that the
rate of different finger nails differs according to the length of
the finger, the most rapid being on the middle then in order the
ring, index and little finger and slowest on the thumb.
Moreover, it is well known among clinicians that nails
exhibit a hypersensitiveness to disease, especially the acute
infectious type as, for example, smallpox, rheumatic, typhoid
and scarlet fever. The writer is now engaged in a study of the
-effect of various diseases and other nutritional disturbances,
such as pregnancy, hyperthyroidism and hypothyroidism, on
the rate of growth of the nails. Concomitant with this study
has arisen the question concerning the relation of the growth of
finger nails to their cystine content.
Much interest in recent year's has been attached to the
physiologico-chemical significance, dietary importance and
therapeutic value of cystine. The chemistry of cystine need
not be dwelt upon here other than to remark that it is a sulfur
compound which forms the basic constituent of keratin, a
substance composing such epidermal derivatives as hair, nails,
hoofs, horns, feathers, et cetera. As to the physiological
.significance of cystine, various workers, notably Hopkins and
Dixon (6), Lewis (7), Lewis and Root (8), have pointed out that
sulfur compounds play an important part in the metabolic
processes of cells, especially oxidation and reduction. Accord244
No. 5
GROWTH OF FINGER NAILS
245
ing to Sullivan and Hess (9) intoxication factors such as bacteria
and toxins tend to deplete these regulators of metabolism and
thus divert them from their normal reservoirs such as nails.
They analyzed the finger nail clippings of 26 normal individuals
and 103 arthritics and found that the average cystine content
of the nails of the normals was 11.69%, whereas the average
for the arthritics was 9.77%. They conclude, therefore, that
this decreased cystine content of the nails of arthritics is an
index of a toxic factor.
In the light of these and other researches it is now believed
by many workers that, notwithstanding the possibility of
numerous etiological agents or predisposing causes, the prime
factor in arthritis and allied rheumatoid conditions is diminished
oxidation resulting from impaired sulfur metabolism—hence the
rationale for parenteral sulfur therapy, many favorable
results of which have been reported in recent years.
In addition to the reports bearing on the chemotherapeutic
action of cystine significant studies have been reported in the
last few years concerning the relation between dietary cystine
and the growth, texture and cystine content of animal hair and
wool. Although the results reported are not unanimous, most
of the evidence presented indicates that the growth and
xiistological structure of these epidermal derivatives depend
largely on the presence or absence of cystine in the diet.
As a result of these various researches concerning the importance of cystine it seemed logical in connection with the writer's
study of the effect of disease on the growth of nails to determine
whether or not there is any marked relationship between the
growth of the nails and their cystine content. The object
of this paper, therefore, is to report the results of a study
based on thirty-five arthritic patients who were under observation and treatment at the Arthritic Clinic of the State Street
Dispensary, College of Medicine, Ohio State University.
METHODS
The method employed for determining the daily rate of
growth of the finger nails was as follows: A mark was made on
«ach nail at the central convex line of the lunula, when present,
t>y means of a sharp, curved scalpel. The daily rate of growth
was ascertained by dividing the distance which the mark
traversed from the anterior margin of the lunula by the number
246
LINDEN F. EDWARDS
Vol. X X X V I I I
of days elapsing from the date of marking to the date of
measuring. Thus let us suppose the distance of the mark from
the lunula in 30 days was 3.2 mm. The daily rate of growth
would be (3.2 mm. divided by 30 days) 0.106 mm. The nails
on which a lunula could not be observed were marked at a
determined distance, usually five millimeters, proximal to the
anterior central border of the nail bed which is visible through
the nail. The distance which the nail grew in these cases was
calculated by subtracting the distance between the mark and the
anterior border of the nail bed from the distance between the
latter point and the mark used as a measuring point. Hence
if the mark was placed at a point 5 mm. from the anterior
border of the nail bed and 30 days later it was 2.8 mm. from the
latter the amount of growth would be (5 mm. minus 2.8 mm.)
3.2 mm. The daily rate of growth, calculated the same as
above, would be (3.2 mm. divided by 30 days) 0.106 mm.
AH measurements were made by means of a Vernier caliper
calibrated in millimeters. In order to insure a fine degree of
accuracy the two measuring arms of the Vernier were sharpened
and the marks on the nails, as well as the adjustments of the
measuring arms of the Vernier to these marks, were made under
magnification with the use of a binocular loupe.
The cystine content of the finger nails was determined by
Miss Edith M. Miller, Department of Pathology, Ohio State
University, who utilized Sullivan's method with a few modifications. The writer wishes to acknowledge his indebtedness to
Miss Miller for furnishing the data on the cystine content of
the finger nail clippings and to Dr. Geo. E. Watson, director of
the Arthritic Clinic, for permission to use the clinical patients
for this study.
In Table I are tabulated the results of the present study on
the rate of growth of finger nails of arthritic patients in relation
to their cystine content.
The rates of growth tabulated here represent the mean daily
rate of growth of all the finger nails of each subject and is
expressed in thousandths of a millimeter. Thus, for example, in
subject G. A. the mean rate of growth of all his finger nails is
.110 mms. daily. The cystine content of the nails of each
subject is shown in the last column of the table and is expressed
in percentage. At the bottom of the table are given the mean
age of the group, the mean daily rate of growth and the mean
cystine content of the nails of all the subjects.
No. 5
247
GROWTH OF FINGER NAILS
Although it is not the object of this paper to make a comparative study of the daily rate of growth or cystine content of
the finger nails of arthritic patients with normal individuals, it
TABLE I
DAILY RATE OF GROWTH OF FINGER NAILS CORRELATED WITH
CYSTINE CONTENT
(35 subjects)
SUBJECT
AGE
SEX
MEAN GROWTH
M
M
M
M
110
118
091
071
G. A
C. B
G. C
W. C
L. C
I. E
A. E
W. F
50
25
59
52
J. F
E. F
L. G
F. G
A. G
53
65
M
M
080
068
56
45
F
M
114
095
R. H
W. H
M. K
C. K
H. K
M. L
G. M
R. M
A. M
E. M
F. M
B. M
O. N
A. N
S. 0
M. S
F. S
H. S
M. S
W. T
E. T
M. V
Mean
. .
. .
.
30
69
M
F
51
62
F
M
123
097
106
128
34
65
50
74
48
20
F
F
M
M
M
F
106
111
104
085
091
094
58
22
49
63
F
M
M
F
112
107
059
091
35
54
44
F
M
M
31
M
103
35
45
F
MF
101
093
51
67
51
68
27
39
39
48.1
F
F
F
M
M
M
131
085
107
089
122
081
107
102
CYSTINE
%
12.0
11.6
12.2
10.5
8.7
14.5
14 2
12.5
6.8
12.5
12.5
11.5
17.6
9.2
9.7
10.1
9.7
11.5
10.2
14.1
13.0
8.3
14.6
12.3
10.6
11.3
12.0
10.2
11.1
9.1
072
122
11.4
10.8
16.5
12.6
11.3
099
11.6
can be observed from the results recorded in the table that in
the case of the 35 arthritic patients studied the mean daily
rate of growth is 0.099 mm. which is essentially similar to
normal, being only 0.001 mm. below one-tenth of a millimeter,
the accepted normal rate. According to Sullivan and Hess (9)
248
LINDEN F. EDWARDS
Vol. X X X V I I I
X
CYSTINE
MEAN
DAILY
RATE FOR ALL NAILS
Fig. 1. The mean daily rate of growth of the finger nails in relation to
their cystine content.
No. 5
GROWTH OF FINGER NAILS
2491
the average normal cystine content of finger nails is roughly
12% as compared with arthritics in which it is in general lower.
As is shown in the table the mean percentage of cystine contained in the finger nails of the 35 patients examined is 11.6%
which is only four-tenths percent (0.4%) below the accepted,
normal.
In regard to the question as to whether or not there is any
correlation between the rate of growth of finger nails and their
cystine content in arthritics it is logical to conclude from the
results shown in Table I and graphically represented in Figure 1
that no such correlation exists. Take for example the cases in
which the cystine content of the finger nails ranges from 12%
to 12.5%, the rates of finger nail growth vary much more
considerably, thus 068 (E. P.), 085 (F. M.), 091 (G. C), 101
(A. N.), 110 (G. A.), 114 (L. G.), and 128 (W. F.) thousandths
of a millimeter. Similarly if we compare the five lowest rates
of nail growth, namely, 059 (R. M.), 068 (E. F.), 071 (W. C),
072 (E. T.) and 081 (H. S.), with their respective cystine content
the range of variation of the latter is likewise quite considerable,
thus 13, 12.5, 10.5, 12.6 and 11.4 percenta. Neither is the
highest mean daily rate of nail growth (131 thousandths of a
millimeter) correlated with the highest cystine content (17.6%)
or the lowest rate (.059 mm.) with the lowest cystine content
(6.8%) or vice versa. Moreover, it is evident that should a
correlation exist between these two factors we should expect
to have either a gradual ascending or a descending curve,
depending of course upon whether a high cystine content
corresponds to a high rate of growth, which we should expect,,
or to a low rate.
SUMMARY AND CONCLUSIONS
1. The problem as to whether the daily rate of growth of
finger nails of arthritics is correlated with their cystine content
was undertaken in view of other researches concerning (1) the
importance of sulfur compounds, such as cystine, to the
metabolic processes of cells; (2) the significance and relation
of cystine of the nails to toxicity and disease, such as arthritis;
(3) the beneficial effects of dietary cystine on the growth of
animal hair and wool.
2. The amount of growth of the finger nails of 35 arthritic
patients used in this study was determined by measuring the
distance which a mark, previously made, grew from the convex
250
LINDEN F. EDWARDS
Vol. X X X V I I I
central line of the lunula of the nail or toward the anterior
border of the nail bed in a given length of time by means of a
Vernier caliper calibrated in millimeters.
3. The daily rate of finger nail growth was calculated by
dividing the amount of growth by the number of days of growth.
Only the mean daily rate of all the nails of each patient was
recorded. Considerable variation in daily rates of finger nail
growth existed between patients. The mean finger nail rate of
the 35 patients was 0.099 mm. daily, which may be taken as
normal, since this figure does not differ significantly from the
accepted normal rate, that is 0.100 mm.
4. The cystine content of the nail clippings of these patients
likewise varied considerably, the mean percentage being 11.6,
which is slightly below the normal (12%).
5. There is no evidence in the present study of any correlation between the daily rate of finger nail growth and the cystine
content of the nails in arthritics.
REFERENCES
(1) Berthold, A. A. Beobachtungen uber das quantitative Verhaltniss der Nagelund Haarbildung beim Menschen, Verhandl. d. Gottingen gelehrten Gesellsch,
1850.
(2) Dufour, M. L. Observations sur la Vitesse d'accroissement des Ongles, Bulletin
de la Societe Vandoise des Sciences Naturelles, 11, 195, 1872.
(3) Sharpey-SchSfer, E. Observations on the relative rate of growth of the nails
of the right and left hands respectively: On seasonal variations in the rate,
and on the influence of nerve-section upon it. Proc. of the Royal Soc. of
Edinburgh, 51, 8, 1930.
(4) Heller, J. Die Krankheiten der Nagel, Berlin, 1900.
(5) Voit, E. tJber die Grosse der Erneverung der Horngebilde beim Menschen,
Zeitschrift fur Biologie, 90, 509, 1930.
{6) Hopkins, F. G. and Dixon, M. On Glutathione. II. A thermostable oxidationreduction system. Jour. Biol. Chem., 54, 527, 1922.
(7) Lewis, H. B. The Metabolism of Sulfur. Jour. Biol. Chem., 42, 289, 1920.
(8) Lewis, H. B. and Root, L. E. Ibid., 50, 303, 1922.
(9) Sullivan, M. H. and Hess, W. C. The cystine content of the finger nails in
arthritis. The Jour, of Bone and Joint Surgery, 16, 185, 1934.